Final touches

Author: Ash Cripps

BuggySemanticInput.mj

@@ -0,0 +1,90 @@
+// Test input for checking symbol table handling
+//**************************************************
+// invoke as:  java MJ.Compiler BuggySemanticInput.mj
+//**************************************************
+
+program P
+  final int  c1 = 'x';
+//----------------| integer constant expected
+  final char cc = 3;
+//----------------| character constant expected
+
+  class C {
+    int f;
+  }
+
+  int i;
+  char ch;
+  C c, c2;
+  char[] a;
+
+     ch x;
+//---| type expected
+     ch[] y;
+//---| type expected
+  char i;
+//-----| i already declared
+
+{
+  void foo (int x) {
+    return 3;
+//---------| void method must not return a value
+  }
+
+  int bar (char c) {
+    if (c > 'x') return; else return c;
+//---------------------| return expression expected
+//-----------------------------------| return type must match method type
+  }
+
+  int main()
+//| must be void
+  {
+    i = 1;
+    int = 3;
+//--| type identifier not allowed here
+    ch = 3;
+//--------| incompatible types in assignment
+    i = 3 * v + 1;
+//----------| v not found
+    x(3, ch);
+//--| called object is not a method
+    read(foo);
+//--------| read object must be a variable
+    read(c);
+//-------| can only read int or char variables
+    print(c);
+//--------| can only print int or char variables
+    foo(3, i);
+//----------| more actual than formal parameters
+    foo();
+//-------| fewer actual than formal parameters
+    foo('x');
+//------| parameter type mismatch
+    if (i == 'a') i = i + ch; else i = i * ch;
+//------------| type mismatch
+//-------------------------| operands must be of type int
+//------------------------------------------| operands must be on type int
+    if (c > c2) c = - c2;
+//------------| invalid compare
+//---------------------| integer operand required
+    i = ch();
+//------| called object is not a method
+    i = new int;
+//------------| class type expected
+    a = new ch[3];
+//-----------| type expected
+    a = new char['3'];
+//---------------| array size must be an integer
+    i = a.f + 3 * c.g;
+//------| dereferenced object is not a class
+//------------------| g not found
+    i = foo[2];
+//-------| bad method call
+    i = ch[2];
+//--------| indexed object is not an array
+    i = a['2'];
+//-------| indexed object is not an array
+//----------| index must be an int
+  }
+}

InvalidScanner.mj

@@ -0,0 +1,16 @@
+Program P
+  {
+    void main()
+    int x, i;
+    char c;
+    {
+      c = 'ab';
+      x = 15;
+      i = 0;
+      @j = int[]; 
+      while (i < 15){
+        print(i);
+        i = i + 1;
+      }
+    }
+  }

MJ/CodeGen/Code.class

@@ -1,9 +1,3 @@
-/* MicroJava Code Generator  (HM 06-12-28)
-   ========================
-This class holds the code buffer with its access primitives get* and put*.
-It also holds methods to load operands and to generate complex instructions
-such as assignments and jumps.
-*/
 package MJ.CodeGen;
 
 import java.io.*;
@@ -113,18 +107,18 @@ public static int get(int pos) {
 	public static void load(Operand x) {
 		switch (x.kind) {
 		case Operand.Con:
-			if (0 <= x.val && x.val <= 5) put(const0+ x.val);
+			if (0 <= x.val && x.val <= 5) put(const0+ x.val); //More efficent put
 			else if (x.val == -1) put(const_m1);
 			else {
 				put(const_);
 				put4(x.val);
 			}
 			break;
-		case Operand.Static:
+		case Operand.Static: //Static operand
 			put(getstatic);
 			put2(x.adr);
 			break;
-		case Operand.Local:
+		case Operand.Local: //Local vars
 			if (0 <= x.adr && x.adr <= 3) put(load0+ x.adr);
 			else {
 				put(load);
@@ -176,8 +170,8 @@ public static void assign(Operand x, Operand y) {
 
 	// Unconditional jump
 	public static void putJump(int adr) {
-		put(jmp);
-		put2(adr);
+		put(jmp); //Put jump instruction in Buffer
+		put2(adr); //Put location of where to jump too
 	}
 
 	// Conditional jump if op is false